| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device and a manufacturing method of the same, which can improve ESD resistance.SOLUTION: In a semiconductor device manufacturing method, by arranging a slit mask 5 when forming a second p-well layer 10, an impurity concentration of the second p-well layer 10 is partially decreased. By forming a second n-off set layer 17 in the second p-well layer 10 having the decreased impurity concentration, a thickness T of the second n-off set layer 17 at this place can be made wider than in the past. By increasing the thickness t of the second n-off set layer 17, a depletion layer 30 does not reach an n-drain layer 22 at low voltage when a reverse bias is applied to a drain thereby to enable prevention of thermal destruction caused by local electric field concentration. As a result, ESD resistance can be improved. In addition, since all that is necessary is to exchange a photoresist mask 3, there is no increase in the number of processes. |
